Don't know anyone who has put a ford diff into a marina car axle.The axle from the marina car is based on a standard / triumph unit and is not the same as the midget / morris 1000 BMC axle. To run in class 7 you must have an axle from the marina range of vehicles. I would keep looking for a marina 10 cwt van axle, or fit a complete Ford unit and run in class 8. CheersPete
As Pete says, I don't think anybody has ever fitted a Ford diff into a Marina car axle. You can fit a low ratio, single wheel axle, Ford Transit diff fairly easily into a 10cwt van axle. I believe it just requires a spacer plate about 5mm thick to fit between diff housing and axle, and then repositioning the diff holding studs on the axle casing. BUT, this of course turns the Marlin into a Class 8 car.I have heard various theories on how to stop diffs breaking, and the only foolproof one is try another type of motorsport!!The cheapest way, I guess, of preserving diffs is to dismantle it, and replace anything that looks duff, maybe have it professional rebuilt, and change the diff oil at least annually. Frank Burton used to fill the complete axle casing with oil, by jacking the car high on one side, removing the halfshaft, and filling with oil.The next way is to replace front and rear suspension from a 10cwt Marina Van. The 10cwt axles are identified by having a wheel stud PCD of 4.5" instead of the normal 3.75" of the car and 5cwt van. If you go down this route try and find an ex-utilities van, ie ex BT, Elect Board, Gas Board, Milk Marketing Board. These vans had modified front suspension to take telescopic shocks instead of lever arm shocks.The only problem with using any van axle is that you do not find many "one lady owner, only used at weekends, always garaged" vans. I've dismantled van axles that looked like they contained tar instead of oil. The advantage of using the van axle is that it is stronger, and of course the diff ratio is lower.Let me assure you Ford diffs, although stronger, still break, its the only Triple I will ever get, breaking them on the Exeter, Lands End, and Edinburgh, although not in the same year!!
It is indeed possible to put a Single Wheel Transit van diff into the 10cwt Marina van casing as it simply requires a spacer plate to move the diff unit forwards as the existing Marina halfshaft splines will mate with the Transit Planet Wheels.This is exactly what we are currently running in the GVSMkII (which is Class 8).For our modification we actually welded the spacer plate to the existing Marina axle casing to reduce the possibility of leaks.The main advantage of the Transit Van diff is that it is relatively easy to get hold of & utilises four planet wheels as opposed to the conventional two. This has the advantage of spreading the load & from our experience of running a twin cam 2.0l engine with plenty of torque when the diff does break (which it certainly will) the diff will lock solid. This locks both wheels together but does not disconnect the drive from the engine thereby preventing the car from becoming stranded on a section (problem is that the car WILL NOT turn corners on the road).Unfortunately I am not sure of the restrictions to axles & casings for Class 7.
Dave's comment is really interesting as I recall that Paul Wear's Fiat Twin-Cam-engined Marlin also ran a Ford diff in a Marina axle and that failed, locking solid, at least twice in one year if my memory serves me correctly. But he did have a lot of power, and used to use it!By contrast, most Marlin owners with a Marina Van diff converted to roller bearings seem to get at least five years of reasonable trialling use out of it before failure and many have got much longer.The ACTC Marlin spec is quite clear and only refers to Rear Axle Casing so a Ford diff in a Marina casing is definitely (currently) OK for Class 7. The ACTC Technical Panel will be discussing this issue at their next meeting (Saturday 15th January) and will, no doubt, report in due course.
Don't know anyone who has put a ford diff into a marina car axle.The axle from the marina car is based on a standard / triumph unit and is not the same as the midget / morris 1000 BMC axle. To run in class 7 you must have an axle from the marina range of vehicles. I would keep looking for a marina 10 cwt van axle, or fit a complete Ford unit and run in class 8. CheersPete
ReplyDeleteAs Pete says, I don't think anybody has ever fitted a Ford diff into a Marina car axle. You can fit a low ratio, single wheel axle, Ford Transit diff fairly easily into a 10cwt van axle. I believe it just requires a spacer plate about 5mm thick to fit between diff housing and axle, and then repositioning the diff holding studs on the axle casing. BUT, this of course turns the Marlin into a Class 8 car.I have heard various theories on how to stop diffs breaking, and the only foolproof one is try another type of motorsport!!The cheapest way, I guess, of preserving diffs is to dismantle it, and replace anything that looks duff, maybe have it professional rebuilt, and change the diff oil at least annually. Frank Burton used to fill the complete axle casing with oil, by jacking the car high on one side, removing the halfshaft, and filling with oil.The next way is to replace front and rear suspension from a 10cwt Marina Van. The 10cwt axles are identified by having a wheel stud PCD of 4.5" instead of the normal 3.75" of the car and 5cwt van. If you go down this route try and find an ex-utilities van, ie ex BT, Elect Board, Gas Board, Milk Marketing Board. These vans had modified front suspension to take telescopic shocks instead of lever arm shocks.The only problem with using any van axle is that you do not find many "one lady owner, only used at weekends, always garaged" vans. I've dismantled van axles that looked like they contained tar instead of oil. The advantage of using the van axle is that it is stronger, and of course the diff ratio is lower.Let me assure you Ford diffs, although stronger, still break, its the only Triple I will ever get, breaking them on the Exeter, Lands End, and Edinburgh, although not in the same year!!
ReplyDeleteIt is indeed possible to put a Single Wheel Transit van diff into the 10cwt Marina van casing as it simply requires a spacer plate to move the diff unit forwards as the existing Marina halfshaft splines will mate with the Transit Planet Wheels.This is exactly what we are currently running in the GVSMkII (which is Class 8).For our modification we actually welded the spacer plate to the existing Marina axle casing to reduce the possibility of leaks.The main advantage of the Transit Van diff is that it is relatively easy to get hold of & utilises four planet wheels as opposed to the conventional two. This has the advantage of spreading the load & from our experience of running a twin cam 2.0l engine with plenty of torque when the diff does break (which it certainly will) the diff will lock solid. This locks both wheels together but does not disconnect the drive from the engine thereby preventing the car from becoming stranded on a section (problem is that the car WILL NOT turn corners on the road).Unfortunately I am not sure of the restrictions to axles & casings for Class 7.
ReplyDeleteDave's comment is really interesting as I recall that Paul Wear's Fiat Twin-Cam-engined Marlin also ran a Ford diff in a Marina axle and that failed, locking solid, at least twice in one year if my memory serves me correctly. But he did have a lot of power, and used to use it!By contrast, most Marlin owners with a Marina Van diff converted to roller bearings seem to get at least five years of reasonable trialling use out of it before failure and many have got much longer.The ACTC Marlin spec is quite clear and only refers to Rear Axle Casing so a Ford diff in a Marina casing is definitely (currently) OK for Class 7. The ACTC Technical Panel will be discussing this issue at their next meeting (Saturday 15th January) and will, no doubt, report in due course.
ReplyDelete